LT4 - DFCO Enabled?

[HumbleMoto]

Hey folks! New member to HP tuners, new owner of a '22 ZLE. I have built up a few cars previously typically limited to bolt ons and never do the tuning myself. In the BMW world I'm comfortable configuring tuning settings with bimmercode and xhp trans stuff but would never touch fueling/spark/torque management. I say this to explain where I'm at from a technical perspective to hopefully get guidance for someone as limited as I am.

'22 ZLE 6M with 3500miles in amazing condition with a ported factory blower, 2'' headers, 2.3 upper pulley and damper, 102mm tb, and big gulp. I bought it in a hurry due to the price point including mods and didn't appreciate how loud/obnoxious it was during the test drive due to my excitement. I don't have a lift but from the looks(and smell) it doesn't have cats. I loathe pops and bangs, gunshots, and general obnoxious noise the car is generating currently although I have no problem with loud.

Ideally some smart folks can look at what I'm doing in the calibration and point me in the right direction.

Attached is the original tune as well as a second file with my edits to stop fueling on decel. I have tried three different calibrations adjusting settings under DFCO; Enable ECT, Enable/Disable RPM, Enable/Disable Speed, none of which made any different for better or worse which was extremely confusing. For clarity, on decel with clutch in there is no pops and bangs which leads me to believe if CFCO is enabled and a good thing, therefore I want DFCO enabled?

If I want DFCO ENABLED then the following should be true?
Enable RPM should be low, something like 1500rpm
Disabled RPM should be high, something like 6500rpm
Enable ECT should be low, something like 0F.
Enable Speed should be low, something like 0mph.
Disable Speed should be low, something like 0mph.
Disable ECT Hyst should be low, something like 32F.

There are a few things I haven't touched out of fear/ignorance, specifically the Enable/Disable for TCC as this is a manual with no torque converter. As well as the Torque tables as ideally all the above logic should have DFCO Enabled and therefore no fuel is sent during decel and therefore no torque management should be required?

My logic may be faulty as I'm way out of my depth, would love to get some wrinkles on my brain. Bonus points if you can point me to the best resource to learn specifically LT4 tuning?

[GHuggins]

Here's the stock tune if it'll help you, but it should also be noted that there is a timer setting that keeps it from entering dfco that we don't have access to. You can also take something like an 18's and take some of the timing tables out of it to help with this too.

[RobZL1]

Greg's right. Copy the top three rows of the minimum spark table from a 2017 or 2018 ZL1, and it significantly reduce the pop-bang. They intentionally introduced more burble in '19, and I think even more in later models by reducing timing on decel.

[HumbleMoto]

Screenshot 2023-07-22 at 12.44.12 PM.png

From the looks of the 2017 (found the repository) 2022 (thank you), and my custom tune the top three rows of Minimum Spark - Base are identical.

[RobZL1]

I can tell you with certainty that 17 and 18 ZL1's have positive values as high as 19 degrees in those rows.

[GHuggins]

Should be long term and base both. Here's a stock man 18 for reference. Yours may have already been changed - I didn't look to be honest, but the 22's had timing right around 0 where the older ones had it right around 18...

[HumbleMoto]

*Edit* Posted from phone and looked like crap

Update: my logic was wrong. I have stopped 80% of the insanity.
Disable RPM should also be low.

I've now found that "delay" folks were talking about, it's about three to five seconds. While that isn't directly tunable, would the base and long term timing potentially help mitigate the pops and bangs further? What ranges of values are considered safe for the first three rows of those tables? Affected by mods?

[TriPinTaZ]

Make sure the DFCO settings are stock and for your transmission type. Auto vs Manual has different settings. Then copy the Minimum Spark table from a 2019 Z06 as a starting point. I've added the file here. You can increase the timing more in the lower RPMs in the top 3 rows if you still get pops.

File 2019 Z06 stk.hpt

[HumbleMoto]

You guys rock! With those factory timings I'm down to what I would call 5% of the original amount of pops/bangs. This is perfect for me.

Two questions remain.
What is the safety level of these settings? I tried to research cylinder mass to understand the conditions/scenario for those tops three rows of the table but don't have a good grasp of what I changed. Timing when airmass(cylinder fill) is low makes me believe this should be a relatively safe setting to change as a layman.

I notice when the RPMs fall idling around the parking lot they drop lower to the point of stalling. If I slip the clutch out without throttle it will cruise fine, when I drive around 1500rpms and just let the engine wind down itself it drops to 500ish and lugs/stalls. With the previous calibrations it would hit 700rpm ish and be fine. So I tried something else, I took the median of each value between the two calibrations and tested that, it was the worst of both worlds, same 20% pops and bangs as well as the falling rpm stumble. I chose the lesser evil and kept the falling rpm issue to avoid the pops and bangs.

[TriPinTaZ]

The minimum spark table is the lowest value of timing allowed to reduce engine torque (rpm, airflow). If it is stalling now, then that area of minimum spark is too low. If you only copied the first three rows of that Z06 file, then that could be the cause too. You would want to copy the whole table.

Another thing you can try is put your stock table back in and adjust the top 2-3 rows in the area you are getting the pops you don't want. Datalog Airmass and RPM to know where you are at. Airmass is just how much air is entering the cylinders.